Crossbr, Sadly there is no quick and easy fix for a dead player but you have a greater chance of recovering an ATJ2085 player because there is more firmware available.
Your only option is to try as many 3.5.35 and 3.5.37 version firmwares you can find that match your screen size. If your player stops responding and is no longer recognised by Windows or the Update tool then you need to short the memory chip to reset the player to ADFU mode and then load a full version firmware.
I would also suggest that you PM member sak_cheegii and provide him with all the details you have listed above. He may be able to help you locate a working firmware with this information.
http://www.mympxplayer.org/privmsg.php?mode=post&u=866